World champion Jorge Lorenzo was fastest as he edged out title rivals Marc Marquez and Dani Pedrosa in practice for Sunday's British Grand Prix at Silverstone.
Lorenzo, 26, has not won any of the last five races to fall 44 points behind championship leader Marquez.
But he was back to his best on Friday, putting his Yamaha top of the timesheets with a commanding lap.
Alvaro Bautista was fourth, with Briton Cal Crutchlow in sixth place.
Repsol Honda rider Marquez, 20, set the best time of a cold morning session with a lap of two minutes 3.816 seconds, but Lorenzo was the man to beat as the track warmed up in the afternoon.
His lap of 2:02.734 was two tenths of a second quicker than Spaniard Marquez's best effort, with 27-year-old Pedrosa nearly half a second behind his team-mate in third and Gresini Honda's Bautista, 28, next.
Nine-time world champion Valentino Rossi, 34, was fifth on his Yamaha, while Crutchlow, 27, will be hoping to improve in qualifying on Saturday after taking pole position on his Yamaha Tech 3 at Brno last weekend.
His fellow British riders Bradley Smith, also of Yamaha Tech 3, and Michael Laverty, of Paul Bird Motorsport, ended the day in eighth and 20th respectively.
In the Moto2 class, championship leader Scott Redding - who signed a deal to race in MotoGP from next season on Thursday - was fastest in the morning session but ended the afternoon in fifth.
Silverstone practice times:
1. Jorge Lorenzo (Spa) Yamaha 2:02.734
2. Marc Marquez (Spa) Repsol Honda 2:02.958
3. Dani Pedrosa (Spa) Repsol Honda 2:03.192
4. Alvaro Bautista (Spa) Gresini Honda 2:03.463
5. Valentino Rossi (Ita) Yamaha 2:03.480
6. Cal Crutchlow (GB) Tech 3 Yamaha 2:03.505
7. Andrea Dovizioso (Ita) Ducati 2:03.658
8. Bradley Smith (GB) Tech 3 Yamaha 2:03.750
9. Stefan Bradl (Ger) LCR Honda 2:03.784
10. Nicky Hayden (USA) Ducati 2:04.089